Improve pip to split transition

When pip to split, flicker usually occured due to the surface
reset transaction applied too late and cuase double offset lead to
surface outside of display then cause flicker.

Fix it by using sync transaction, and also try to do this transition
in a WCT rather than two.
(Before this CL, we will add pip task to split root as one WCT, and
active split as another WCT).

Fix: 272446831
Test: manual
Test: pass existing tests
Change-Id: I6d59bd4084862e15a337c755cbad73d26a71e5aa